Description: The Existing_Use_Segments feature class provides a geospatial representation of the existing use class information provided on MDE's website for Maryland stream segments with a specified cool / cold water existing use determination. For more information on existing uses and to view all completed existing use determination documents, please refer to MDE's Existing Use webpage, linked here: https://mde.maryland.gov/programs/water/TMDL/WaterQualityStandards/Pages/Existing-Use-Determinations.aspx.
Copyright Text: MDE’s Water and Science Administration would like to acknowledge the USGS for their 1:24,000 scale National Hydrography Dataset Plus version 2 which was used during the development of this line file.
Description: The Rivers and Streams feature class is a geospatial representation of linear bodies of water (e.g. rivers, streams, etc.) within Maryland's borders. This update to the feature class does not include artificial paths through impoundments, tidal waters, or tidal coastlines. The Rivers and Streams feature class uses the high resolution NHDPlusV2 (1:24,000 scale) produced by the United States Geological Survey (USGS). This particular file provides the Maryland use class assigned to each linear body of water as specified in Code of Maryland Regulations (COMAR) 26.08.02.08. The dataset is intended to be used in conjunction with the information found in the regulation. By linking Maryland stream use classifications with the NHDPlusV2 through the permanent identifier code, the information contained in this dataset can be analyzed using software tools ranging from spreadsheets to geographic information systems (GIS) to aid in regulatory decision making. Basing the Maryland use class dataset upon a national stream dataset like the NHDPlusV2 facilitates the sharing of geospatial information with other organizations that can be integrated into many different types of applications.This feature class provides the use class (UC) designation as determined by MDE, the regulatory agency responsible for assigning UCs, and is derived directly from the State of Maryland's stream segment designations as described in the Code of Maryland Regulations (COMAR) 26.08.02.08. Specific UCs identified within this feature class include Use I, Water Contact Recreation, and Protection of Nontidal Warmwater Aquatic Life; Use II, Support of Estuarine and Marine Aquatic Life and Shellfish Harvesting; Use III, Nontidal Cold Water; Use IV, Recreational Trout Waters, and all Public Water Supply uses (I-P, III-P, IV-P).
Copyright Text: MDE’s Water and Science Administration would like to acknowledge the USGS for their 1:24,000 scale National Hydrography Dataset Plus version 2 which was used during the development of this line file.
Description: Note: This single feature class is one of a set of feature classes (3) that geospatially depict Maryland's surface waters (streams/rivers, tidal water bodies, and impoundments). The Impoundment feature class is the official geospatial representation of the major impoundments managed within Maryland. Other impoundments do exist, however, they may have limited access (privately owned) or they may be small (<5 acres) in size and therefore are not part of the state's regulatory water quality monitoring.To create this file, MDE started with the NHD water body feature class. In cases where the NHD water body feature class did not accurately represent the extent of an impoundment, the impoundment was hand-traced using high resolution aerial photography, and MDE assigned a new ComID. Not all impoundments in Maryland were included in this shapefile. This was purposefully done as thousands of impoundments exist and many of these are not regularly assessed by the state. However, impoundments may be added to this shapefile in the future should new ones be created or should the state find the need to identify their use class. The 2019 update included thirteen impoundments which were not included in the 2014 update. The 2023 update reflects revisions to COMAR 26.08.02.08 completed through the 2019 Triennial Review of Maryland's Water Quality Standards.Note: COMAR regulation may be accessed via the following link: https://dsd.maryland.gov/regulations/Pages/26.08.02.08.aspx. Even though this data set is the best visual representation of the uses described in COMAR, when any discrepancies occur between this dataset and COMAR, always default to COMAR. Caution should be exercised when using this file to generate data regarding use extent (in impoundment acres or other geometric length) as the size in the attribute table reflects the area of impoundment calculated using the Maryland State Plane Meters (NAD 1983) projection. Also, designated uses herein only apply to waters within the State of Maryland, whose borders and NHD segmentation do not always match.By having Maryland’s water body use classifications linked to a common identifier (COMID) code, the information contained in the dataset can be analyzed using software tools ranging from spreadsheets to geographic information systems (GIS) to aid in regulatory decision making.
Copyright Text: MDE’s Water and Science Administration would like to acknowledge the United States Geological Survey for their 1:24,000 scale National Hydrography Dataset upon which this file was based.
Description: The Tidal Waters feature class is the geospatial representation for tidal bodies of water (e.g. Chesapeake Bay, tidal tributaries to the Chesapeake Bay, Coastal Bays, and Atlantic Ocean) within Maryland's borders. This feature class is built upon the Chesapeake Bay Program's salinity segmentation scheme and Maryland's coverage for the Coastal Bays. Note: This single feature class is one of a set of feature classes (3) that geospatially depict Maryland's assessment units in non-tidal streams, tidal water bodies, and impounded waters. By linking Maryland's water body use classifications through the common identifier (COMID) code, the information contained in the dataset can be analyzed using software tools ranging from spreadsheets to geographic information systems (GIS) to aid in regulatory decision making. Please note: Where a water body endpoint and use class limit identified in COMAR differed, the segment was assigned the more stringent use class. Five tidal areas on the eastern shore were added by MDE, Water and Science Administration (SSA) staff in June 2017 based on the Maryland SixInchImagery. Modifications were made to the shorelines in those areas to better represent several smaller embayments of Chincoteague Bay and Newport Bay.
Copyright Text: MDE would like to acknowledge the Chesapeake Bay Program for their Chesapeake Bay Segmentation layer which was used during the development of this polygon file. MDE would also like to acknowledge the USGS for their 1:24,000 scale NHD which was used to help determine shoreline extents in tidal waters.